Feb 22: Is it dark energy, or is time just different in space? And more...
Stone-Age cannibalism, elephant seals do science, rabbits eat teeth, and our ears used to be gills
On this week's episode of Quirks & Quarks with Bob McDonald:
Scientists are recruiting elephant seals to learn more about the oceans' twilight zone
Below about 200 metres there's still a lot going on in the ocean, but it's tremendously hard to observe and understand even with modern technology. Scientists from the University of California, Santa Cruz have maintained a long-term monitoring study of elephant seals. The team, including PhD candidate Allison Payne, has discovered they can use the seals as scientific sentinels, to help humans better understand the conditions of the dark deep sea. The research was published in the journal Science.
A detailed study of the remains of ten individuals who lived — and died — 18,000 years ago in Poland has revealed that they were butchered and probably eaten as the final act in a prehistoric conflict. Characteristic cut marks on their skulls and bones show that they were systematically de-fleshed, before their fragmented remains were tossed aside. This research was led by Francesc Marginedas, a PhD candidate at the Catalan Institute of Human Palaeo-ecology and Social Evolution in Tarragona, Spain. Their research was published in Scientific Reports.
Evolution tends to re-purpose things, even as it massively transforms organisms outwardly. A fascinating example is the new finding that the unique cartilage in our external ears seems to have once been gill tissue from our ancient fish ancestors. Gage Crump from the University of Southern California made the discovery using a series of gene-editing experiments on zebrafish. The research was published in the journal Nature.
Rabbit teeth constantly grow during the life of the rodents, which means they need calcium to regrow them. A new study suggests that one of the ways rabbits supply calcium for their teeth is by ingesting and recycling the tooth material that grinds off as they chew. Dr. Johanna Mäkitaipale is a veterinary orthopedic surgeon and a postdoctoral researcher at the University of Helsinki, Finland. She led this research, which was published in The Veterinary Journal.
For more than two decades, cosmologists have been invoking the idea of a mysterious dark energy to explain observations that appeared to show an acceleration in the expansion of the universe. But more recent observations are adding weight to a different theory that does away with the dark energy. Ryan Ridden, an astronomer from the University of Canterbury, said the "timescape theory" suggests time simply runs differently in the large empty regions of the universe. Their study is in the journal Monthly Notices of the Royal Astronomical Society.
READ MORE: A competing theory to 'dark energy' suggests the universe has different time zones
